Vertical laser cavity with a non-planar top mirror

Abstract

A vertical laser cavity includes a non-planar top mirror in order to improve the optical performance of the laser cavity. In one approach, the top mirror is curved to form a plano-concave geometry with the bottom mirror, as opposed to the typical plano—plano geometry. This can reduce diffraction losses and otherwise improve optical performance.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 60 / 365,466, “Vertical laser cavity with a non-planar top mirror,” by Daniel A. Francis and Chris Decker, filed Mar. 18, 2002. The subject matter of the foregoing is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates generally to semiconductor-based vertical laser cavities (e.g., as used in VCSELs). More specifically, the top mirror of the laser cavity is non-planar, thus enhancing the performance of the laser cavity.[0004]2. Description of the Related Art[0005]As the result of continuous advances in technology, optical devices are becoming more important and more prevalent. For example, the increasing demand for communications bandwidth has resulted in an increased interest in optical communications systems, including those that transmit data over opti...

AI Technical Summary

Benefits of technology

[0009]The present invention overcomes the limitations of the prior art by providing a vertical laser cavity in which the top mirror is non-planar, thus improving the optical performance of the laser cavity. In one approach, the top mirror is curved to form a plano-concave geometry with the bottom mirror, as opposed to the typical plano-plano geometry. This can reduce diffraction losses and otherwise improve optical performance.

[0010]In one embodiment, an optical device includes a planar bottom mirror, a buried active region (e.g., a buried heterojunction) and a non-planar top mirror all integrated on a substrate. The two mirrors form a vertical laser cavity. A current path traverses the buried active region. Electrically pumping the buried active region provides gain for the vertical laser cavity.

Problems solved by technology

One drawback of vertical laser cavities is they can be difficult to fabricate and operate.

This results in relatively low gain for each round trip.

Otherwise, lasing cannot be achieved.

However, their design is often driven by fabrication limitations, resulting in less than optimal mirror designs.

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